Sealing device



p 71943- H. HORNSCHUCH 2,329,990

SEALING DEVICE Filed Feb. 12, 1942 INVENTOR Han/12s Hovaschuclv BY q HI 5 ATTORNEY.

Patented Sept. 21, 1943 sh ame enrich Hanns Honrschuch, Easton, Bas' assignor to IngersolhRand Company, New.

cornoretion 0t Jersey York, N. Yr, a

eg icati h. Echru r 2 1. .42... er a NQ- .30.5 1.

1 Clam (Cl. 2.86:3),

This invention relates to. sealing devices, and

more particularly to a sealing device for a centrifugal pump and the like.

The invention is intended more particularly for use in-connection with sealing devices of the typeknown as mechanical seals comprising apair of sealing components which cooperate to effect a seal and operate in such wise as; to. valve a limited quantity f. liquid therebetween in order to minimize wear on their sealing surfaces.

As is customary in devices of this naturev one component is carried by a rotary member, as for example a shaft of a centrifugal pump and, therefore, rotates with the shaft but is, incapable of longitudinal movement other than such slight endwise movement as may occur by reason of the natural clearances between the rotor of thepump' and the elementsserving as abutinen ts therefor.

The other sealing component is restrained against rotary movement but is capable oi moving longitudinally with respect to. the rotor and, therefore, with respect tov the sealing component carried by the. rotor.

It is an object of the present invention to avoid undue wear of the surfaces serving the sealing function. More specifically, it is an object to id h app ication of e c ssive. p essure .to the ia e o th wmm lW a n cmhe ch n thereby obviate the changes of damaging the. seal,- ing surfaces.

Another object is to simplify the construction of the sealing device so, that it may be readily serviced and maintained with a mini um of expense.

other'obi cts will be in part obvious and in part pointed out hereinafter.

The figure in the accompanying drawing is. a longitudinal, elevation, partly in section, or a sealing device constructed in accordance with the practice of the invention and a portion of a centrifugal pump. to v which it applied.

Referring more particularly to the drawing, 26 designates, in general, the sealing device constructed in accordaunee with the practice of, the invention and device.

The pump comprises a casing 22 having a shaft 23 extending horizontally therethrough and an impeller. 2 moun ed. 9 h is ai Th me cr m y be t e. fina s ag e e a ulti ta e hump a he id handle by passes through an inlet chamber 25t the eye 25 of the impeller and is discharged into a pumping chamber 21 containing the impeller.

In the arrangement shown the wall 28 con- Z! a pump embodying the sealing the flange 42.

i t h th'c r bounding u ac i the. pumpinc mber als fo ms. bound n su ace e a 10w pr ss r v r ba an n hamber 3.9. having n Outlet passa e 3D hat m y mmuni ate. in a Well known manner, with the inlet chamber (not hown). of the uma e hhi c tehds h ugh the. wa wh ch has a bore 3] of considerably larger diameter than h h t for the accommodati n o a. l eve 3. h v n an external flang at i s outer chi throu which extend bolts. 34, cr ccuif he. the sleeve fixedly to the wall 28. A gasket. 351$ interposed between an external shoulder 35 on the eve. 32 and a, sh lder i th 'h -rc 3. t0

p et t the lea age of liquid. along. the. out Surface of thesleeve.

r ahe dc the rt n o he shaft lying within the sleeve .32 is a balancing drum 313 that v he d a a nst otar m m nt with. esp ct to the sha t by he y 9. w i h c r th mpel er 24- i th aft; m r nd c e ba a cin drum seats a ainst the hub of the impeller 2t and h p ti n f ai hd i e a anc ng d u lyin exte i y cf th hub of the impe l r ohst l c s ur su fa e fi l h t i o s an ly subjected to the pressure of the liquid in the pum he c m e 2 The balancing drm'n 33 is held against the irr pe e b a h t rea e pon t h .t 24% and seating against the outer end. of thebaiancing drum. This end of the balancing carries an external flange l2 that overlies thes ieeve 32 and the outer end surface of the balancing drum constitutes a pressure surface tii'that is subjected to the pressure of" the liquid Within the balancing chamber 29. The peripheral surface of the balancing drum 3% is grooved to form a labyrinth 44 that preferably extends from the inner end of the balancing dru to a point near In the form of the invention illustratedthe inner surface of the flange 42 constitutes a sealing surface 45 that cooperates with a sealing member 4 6, for controlling the flow of liquid from the pumping chamber 21 through thesleeve 32 t0 the balancing chamber 29;. The sealing member 46 is of ring-shape constructed oflcgrbon and arranged directly about the balancing drum In. view I he fra ile. natu e. cfthe a er a Q whi h. the s a ihsmemhcr 4 is constru ted it is desirable that the said member be suitably supported on its peripheral surface. To this end th sealing member is arranged in a holder 41 lying in a recess 48 in the sleeve 32. The holder 4! is in the form of a ring that i slidable endwise within the recess 48 so that it may be freely responsive to the forces acting thereagainst for maintaining the sealing member 46 in the correct sealing relationship with the sealing surface 45. A pin 49 seated in the sleeve 32 extends into a notch 50 in the inner end of the holder to prevent rotation of said holder with respect to the sleeve 32.

The bore of the holder 41 is of sufliciently larger diameter than the balancing drum to avoid contact between the two, and in the periphery of the holder is a sealing ring 5! to prevent the passage of liquid along the outer surface of the holder.

The recess 48 is provided at its outer end with an enlarged portion 52 to accommodate an external flange 53 of the holder 41 which has an annular internal recess 54 that opens into the bore of the holder to receive the sealing member 46. The flange 58 is thereby provided with a cylindrical skirt 55 that overlies and engages the periphery of the sealing member 46 so that the force of the liquid within the sealing member will be ineffective to fracture it. The sealing member is of such diameter that it will slide readily into the recess 54 but is held against rotation with respect to the holder by a pin or pins seated in the flange 53 and extending into the sealing member.

As will be readily apparent from the foregoing description of the sealing device, the recess 54 is in direct communication with th liquid flowing along the periphery of the balancing drum 38 and liquid may, therefore, find its way between the rearward end surface of the sealing member and the bottom 51 of the recess which serves as a seat for the sealing member. In order, therefore, to prevent the sealing member 45 from being moved outwardly in the recess by the force of such liquid and to prevent liquid under pressure from finding its way between the periphers of the sealing member and the skirt 55 the rearward end of the sealing member is provided with an annular groove 58, and in the flang 53 are ports 59 to communicate the annular groove 58 with the clearance space 6!! existing between the flange 53 and the bottom of the recess 54 and also encircling the cylindrical skirt 55. The space is in communication with the balancing chamber 29 through a gap 5! defined by the inner surface of the flange 42 and the adjacent portion of the sleeve 32.

The annular groove is preferably located midway between the inner and outer surfaces of the sealing member and the portion of the end surface of the sealing member lying inside the groove constitutes a sealing surface 46' that engages the bottom of the recess 54 to prevent the excessive leakage of liquid into the annular groove 58. The portion of the end surface of the sealing member lying outside of the annular groove 58 also constitutes a sealing surface 45 and cooperates with the bottom of the recess 54 to prevent the 'flow of liquid from the annular groove to the periphery of the sealing member.

In order that the holder may be s bjected to a force that will predominate slightly over the pressure gradient existing between the sealing surface 45 and the sealing member 46 the inner end of the holder is suitably proportioned to serve as a pressure surface 62, the recess 48- being of Ill) suitable depth so that the liquid may enter freely from the labyrinth into the inner end of the recess 48 against the pressure surface 62.

From the foregoing description it will be readily apparent that liquid flowing from the pumping chamber 21 through the sleeve 32 will act against the pressure surface 62 to maintain the flange 53 against the inner end of the sealing member and to hold the sealing member in the correct relationship with the surface 45. In these positions of the sealing elements only a 'sufficient amount of leakage takes place between face 45 by the pressure of the liquid acting against the pressure surface 62.

During this operation of the device, some liquid will enter between the bottom 51 of the recess 54 and the adjacent surface of the sealing member. However, upon reaching the groove 58 such liquid will passv through the ports 59 and the spaces 5t and 6! into the balancing chamber 29 instead of acting to separate th holder 41 and the sealing member 48 and possibly thrusting the latter with undue force against the sealing surface 45.

In practice, the present invention has ee found to be highly effective as a sealing device for use in connection with the relativelystationary and rotary elements of a centrifugal pump. It requires only a few parts of simplified design and the sealing member may be quickly replaced without necessitating prolonged idle periods of the pump. The sealing member is, moreover, of simplified design so that its renewal will involve only a minimum of expense.

I claim:

A sealing device, comprising a casing having a bore subjected to fluid under pressure and a low pressure zone, a rotary member in the bore having a sealing surface, an annular sealing member encircling the rotary member to seat at one end against the sealing surface to valve 21 restricted flow of fluid medium from the bore outwardly along the sealing surface and having an annular groove in the other end to receive fluid medium flowing outwardly from the bore along said other end of the sealing member, a holder slidable endwise in the casing having an annular recess in communication with the bore to receive the sealing member, a flange on the holder to engage the peripheral surface of the sealing member, a seatingsurface in the recess for said other end of the sealing member, sealing surfaces on the opposite sides of th annular groove to engage the seating surface, there being a passage through the holder communicating the groove with the low pressure zone to provide an outlet for fluid medium flowing outwardly from the bore into the annular groove, and a. pressure surface on the holder subjected to the fluid medium in the bore to urge the holder and the sealing member toward the sealing surface.

HANNS HORNSCHUCH. 

